Various methods are being studied for imaging technology to obtain information (distance information) of the depth direction as two-dimensional array information such as technology using a reference beam, stereoscopic ranging technology using multiple cameras, etc. In particular, in recent years, the demand is increasing for relatively inexpensive products that can be used as novel input devices in consumer applications.
Among such imaging technology to obtain the distance information, methods that dose not use a reference beam for measuring are called passive methods. Passive methods include a parallax method based on triangulation, an image estimation method that estimates the distance from experience based on the configuration, contrast, and the like of the acquired image, etc. In particular, a parallax method has been proposed in which various calculation methods use a binocular configuration as the basis. For imaging technology that obtains the distance information using the parallax method, it is desirable to perform the distance measurement (the ranging) for a wide area with high precision.